Rotary engine.



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ROTARY ENGINE.

(Application filed July 5, 1898.)

(No Model.) 3 heats-Sheet 2.

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No. 644,663. Patented Mar. 6, I900.

' A. DAHLIN.

ROTARY ENGINE. f

(Application filed July 5, 1898.) (No Model.) 3 Sheets-Sheet '3,

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ANDRElv DAHLIN, OF VASA, MINNESOTA.

ROTARY ENGINE.

SPECIFICATION forming part of Letters Patent No. 644,663, dated March 6, 1900.

Application filed July 5, 1898. Serial No. 635,143. (No model.)

T all whom it may concern.-

Be it known that I, ANDREW DAHLIN, a citizen of the United States, residing at Vasa, in the county of Goodhue and State of Min-, nesota, have invented certain new and useful Improvements in Rotary Engines; and I do hereby declare the following to be afull, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to rotary engines, and has for its object to provide a simple and durable engine of this type which will have the maximum of efficiency; and to this end my invention consists of the novel devices and combinations of devices hereinafter described, and defined in the claim.

The preferred form of my invention is illustrated in the accompanying drawings, wherein like characters indicate like parts th roughout the several views.

Figurel is a side elevation of myimproved engine. Fig. 2 is a transverse vertical section taken on the line a m of Fig. 1 looking toward the right. Fig. 3 is a transverse vertical section taken on the line 00 m 'of Fig. 1 looking toward the right. Fig. 4. is a transverse vertical section taken on the line 22 00 of Fig. 1 looking toward the right. Fig. 5 is a transverse vertical section taken on the line 12 m of Fig. 1 looking toward the right, the positions of the piston and oscillating abutments being shown by dotted lines, although, in fact, these latter parts stand to the left of said section-line. Fig. 6 is a detail view of the rotary piston, principally in plan view, but partially in section. Fig. 7 is a perspective view of one of the oscillating abutments. Fig. 8 is a view which is identical with Fig. 5 except that the parts are shown in different relative positions, and Fig. 9 is a horizontal section taken approximately on the irregular line 00 00 of Fig. 3.

The body of the cylinder-casting is made of three sections 1, 2, and 3 and a steam-chest plate or cover 4, which parts are rigidly but detachably secured together by nutted bolts or studs 5 and 6. The main bore of the cylinder, or, in other words, the piston-seat 7, and the seats 8 for the oscillating abutments are formed principally in the section 1; but they extend slightlyinto the sections 2 and 3.

The exact relation of the piston-seat 7 to the seats 8 will more clearly appear from the following description of the piston and the oscillating abutments but it may be here noted that said seats 8 stand diametrically opposite to each other and parallel to said seat 7, and both intersect the said seat 7.

Between the sections 3 and 1 a live-steam chest 9 and an exhaust-chest 10 are formed. As shown, the exhaust-chest 1O partially surrounds the live-steam chest 9. Four admission-ports 11 and 11 open from the live steam chest 9 into the piston-seat 7 through the section 3. Likewise four exhaust-ports 12' and 12 open from the exhaust-chest 10 into the seats 8 through said section 3. The admission-ports 11 and 11 are positioned in pairs, one over the other, and each pair is adapted to be opened and closed by a rotary valve 13, provided with a pair of passages that extend at angles to each other, so that the ports 11 11*, controlled thereby, will be opened and closed in reverse order. Like wise the exhaust-ports 12 12 are positioned in pairs, and each pair is adapted to be opened and'closed by a rotary valve 14:, provided with passages that extend at angles to each other, so that said valve will open and close the cooperating ports 12 and 12 in reverse order. The valves 13 and 14:, respectively, are provided with arms 15 and 16, the free ends of which are connected by links 17, so that said valves will be simultaneously moved.

'A pair of double-ended vibrating valves 18 cooperate one with each pair of admissionports 11 11 to open and close the same in reverse order. These valves 18 are carried by short rock shafts 19, that project through the cylinder-section 4, (as shown,through stuffingboxes 20) and are provided at their outer ends with short arms 21, the free ends of which are pivotally connected to a vibrating bracket 22, having a centrally-located rectangular opening 23.

24 indicates a steam-so pply pipe which opens into the live-stean1 chest 9, and 25 indicates an exhaust-pipe which opens from the exhaustchest 10.

The piston shaft 26 extends centrally through and is journaled in the cylinder-sections 2, 3, and 4, and within the cylinderbore or piston-seat 7 it is provided with a cy-' lindrical piston-head 27, which in diameter is considerably less than said seat 7. Between radially-projecting flanges 28 of the piston-head 27 a spring pressed propellingblade or packing-strip 29 is mounted to work with its outer face in contact with the cylindrical surface of the seat 7. Light springs 30 press the said blade or strip 29 outward. The ends of the blade or packing-strip 29 are beveled so as to form a miter-joint with correspondingly-beveled ends of cooperating end packiugs 31. These end packings 31 work in the countersunk extremities of the seat formed between the flanges 28, and they are pressed radially outward by light springs 32 and into contact with the ends of the pistonseat by means of light coiled springs The springs 30, 32, and 33 cooperate to force the packing-strips 29 and 31 into contact with the cylindrical and fiat surfaces of the pistonseat. Annular packing-rings 34, pressed outward by springs 35, mounted in suitable seats in the ends of the piston 27, form steam-tight joints between the ends of said piston and the ends of said cylinder, and thus prevent steam from escaping through the bearings in which the shaft 26 is mounted.

In each of the seats 8 an oscillating abutment or reaction-block is mounted. These abutments 36 have cylindrical contours and snugly fit their seats 8, and they have projecting shafts 37, that are provided with crankarms 38, which, as shown, carry antifrictionrollers 39 at their free ends. Very close to its ends each abutment 36 is provided with peripheral packing-rings 40, and, extending almost the entire distance between the packing-rings 40, it is also provided with a cylindrical longitudinally-extended concavity 41. The oscillating abutments 36 when thus mounted in their seats are positioned with their peripheries tangential to the body of the rotary piston 27, and the concavities 41 are formed on such curves that when properly turned they will complete or make up the true cylindrical surface of the piston seat or bore of the cylinder. Each oscillating abutment is provided with a spring-pressed peripheral packing strip 42, which extends adjacent to one edge of the concavity 41 in that peripheral portion thereof that is at times turned into complete transverse contact with .the piston-head 27. Each oscillating abutment 36 has a pair of exhaust-ports 43 and 43. The ports 43 extend from the ends of the respective abutments to the in termediate peripheral portions of the same, and the ports 43 extend from the same ends of said abutments to the concavities 41. The discharge ends of said ports 43 and 43 will, when the abutments are in the positions indicated in Figs. 2, 3, 4, and 5, register, respectively, with the exhaust-ports 12 and 12 Between the exhaust-ports 43" and 43 and on their outer sides said abutments are further provided with longitudinally-extol]dod spring-pressed packing-strips 44.

On its right-hand end the piston-shaft 26 is provided with a disk 45, in which a profile cam-groove 46 is formed. The rollers 39 on the free ends of the arms 38 work in this camgroove 46. On its left-hand end said shaft 26 is provided with a pulley 47, over which a belt (not shown) may run to transmit the power and motion from the engine.

Just inward of the vibrating rack 22 the piston-shaft 26 is provided with a disk 48, which carries a crank-pin or antifrictionroller 49, which when the piston and disk 48 are in motion will strike alternately against the opposite sides of the rectangular opening 23, and thus, through the connections already described, will oscillate the vibrating valves 18 in reverse order. In order to permit the engine to be reversed or run in either direction in which it is started, the disk 48 is permitted a limited oscillation on the pistonshaft, this, as shown, being accomplished by the cooperation of a key 50, carried by said piston-shaft 26, and a segmental keyway or groove 51 in said disk 48.

Attention is here called to the fact that in Fig. 4 the positions of the admission-ports 11 and 11 are indicated by dotted lines, although, in fact, these ports are actually in that end of the cylinder-casting which in Fig. 4 is cut away.

The operation is substantially as follows: Let it be assumed that the valves 13 and 14 are set and the other parts occupy positions as indicated in Figs. 1, 2, 3, 4, 5, and 9. In these set positions of the valves 13 and 14 they respectively open the admission-ports 11 and exhaust-ports 12 and at the same time close the admission-ports 11 and exhaust-ports 12. Hence so far as the action immediately to be described is affected the ports 11 and 12" may be treated as if they did not exist. In the position indicated by the figures just noted the right-hand admission-port 11 is closed by the lower end of the vibrating valve 18, while the left-hand admission-port 11 is open for the admission of live steam therethrough into the piston-seat 7, between the left-hand abutment 36 and the back or left side of the propelling blade or projection 28 29. As the left-hand exhaust-port 12 is closed, as previously noted, the expansion of the steam will react against the left-hand abutment and said propelling projection 2829 and cause the piston 27 to rotate in the direction indicated by arrows marked on said Fig. 4. As the right-hand exhaust-passage 12 is opened both by the valve 14 and the vibrating valve 18 and its registration with the righthand port 43", no resistance will be offered to the advance movement of the piston.

By reference to Fig. 5 it will be noted that the cam-groove 46 stands in position to begin to force the right-hand arm 38 outward. By the time the propelling projection 28 20 reaches the right-hand seat 8 the concavity 41 of the right-hand abutment will be turned into line with the cylindrical surface of the piston-seat 7, as shown in Fig. 8, so that the bearing-surface of the packing-section 29 will freely pass the abutment. After said packing-section 29 has passed the right-hand seat 8 the right-hand abutment will be restored to the position indicated in Figs. 4 and 5, and at this time the lower end of the right-hand vibrating valve 18 will be moved so as to open the right-hand admission-port 11, thereby admitting live steam between the propelling projection 28 29 and the right-hand abutment 36. At this same time the left-hand exhaustpassage 12 is open, so as to permit the free exhaust of the fluid in front of the propelling projection of the piston. These actions just indicated will be automatically kept up and repeated, so that the piston will be given continuous motion in the direction indicated by arrows marked on the various figures.

In order to reverse the engine, it is necessary, first, to shift the valves 13 and 14 so that they will close the ports 11 and 12 and open the ports 11 and 12 This being accomplished, the engine may be run in the re verse direction. Under this reverse movement of the piston and its shaft the disk 48 and its roller 49 will slip backward with respect to the piston-shaft a distance equal to the length of the slot 51, so that under this reverse movement the vibrating Valves 18 will have the properly-timed action with respect to the movements of the abutments 26. Before leaving this description of the operation it is important to call attention more specifically to the timed relation of the movements of the pair of cooperating abutments. By directing attention to Fig. 5 the relation of the cam 46 to the operating-arms 38 and their rollers 39 will be clearly seen. The operatingrollers 39 stand diametrically opposite each other, and the divergency of the cam 46 from its smallest cylindrical surface or circle is confined to slightly less than one-half of a complete rotation, or, in other words, to less than one hundred and eighty degrees. From these relations it follows that the particular abutment against which the steam is reacting to propel the piston will be held stationary in its operative position while the opposite abutment is being moved to permit the passage of the propelling blade or projection of the rotary piston and until this latter abutment has been moved backward to its operative position, in which position live steam is admitted in advance of this said latter-noted abutment. In virtue of this arrangement live steam is always active upon the propelling projection or blade of the rotary piston. The importance of this action is very obvious. It gives a continuous application of the driving power and leaves no dead-point at which the propelling projection of the piston can possibly stop, so as to make it impossible to start the engine by the simple action of turning on the steam.

\Vhat I claim, and desire to secure by Letters Patent of the United States, is as follows:

In a rotary engine, the combination with the cylinder and the rotary piston having the propelling projection, of the pair of oscillatingabutm ents tangentially engaging said piston, provided with cylindrical concavities adapted to complete the cylinder-bore, and provided each with the pair of exhaust-ports, two independent pairs of admission-ports opening into said cylinder, a pair of vibrating valves operating to open and close said ad mission-ports in reverse order, means for oscillating said abutments with a properlytimed action, and a series of connected valves for simultaneously opening and closing the cooperating members of said pairs of admission and exhaust ports, whereby the engine may be reversed, substantially as described.

In testimony whereof I affix my signature in presence of two witnesses.

ANDREW DAHLIN. Witnesses:

HARRY KILGORE,

J AS. F. WILLIAMsoN. 

